Drinking Water Quality Report

Transcription

1 water efficient the more stars more The litres per minute 7.5 WATER RATING Drinking Water Quality Report 2017

2 Glossary of Terms Term ADWG 2011 DHHS E. coli HACCP mg/l NTU orgs/100ml Regulations (2015) Section 22 notification Definition Australian Drinking Water Guidelines Published by the National Health & Medical Research Council of Australia. Victorian Department of Health and Human Services Escherichia coli, a bacterium which is considered to indicate the presence of faecal contamination and therefore, health risk. Hazard Analysis and Critical Control Points certification for protecting drinking water quality Milligrams per litre Nephelometric Turbidity Units Organisms per 100 millilitres Safe Drinking Water Regulations (2015) Victoria Notification under Section 22 of the Safe Drinking Water Act 2003 of known or suspected water contamination < less than symbol. > greater than symbol

3 Table of Contents 1. Introduction Characterisation of the system Source water system City West Water system 4 2. Water treatment and quality management system Water treatment Issues 6 3. Emergency, incident and event management 7 4. Drinking Water Quality Monitoring 8 5. Drinking Water Quality Standards Escherichia coli (E. coli) Total trihalomethanes Turbidity Summary performance against water quality standards Other water quality standards (algae toxin, pathogen, chemical or substance that may pose a risk to human health) Aesthetic characteristics Analysis of results trends Historical compliance of standard parameters Parameter trends over time and between localities Complaints relating to water quality Risk management plan audit results Undertakings under Section 30 of the Safe Drinking Water Act Exemptions from water quality standards under Section 20 and conditions imposed under Section 21 of the Safe Drinking Water Act Variation to aesthetic standards under Section 19 of the Act and conditions imposed under Section 21 of the Safe Drinking Water Act Regulated water Further Information 24 Appendix A: Water quality data by locality 25 Appendix B Spatial and time-based water quality summaries 41 Appendix C 2016 Risk Management Plan regulatory audit certificate 50

4 From our Managing Director Welcome to City West Water s 2017 Annual Drinking Water Quality Report. Each year we produce a report to update our customers and the community with details of the quality of drinking water that we are supplying throughout our service area. This 2017 report addresses the 12 month period between 1 July 2016 and 30 June In 2016 City West Water launched a new corporate strategy to be an exceptional service provider that puts customers first and benefits the community. Water is a life-giving resource; its provision contributes to community health and hygiene. We strive to deliver our services in a reliable and affordable way that is accessible to everyone in our community. Our service area is growing and encompasses the inner and western suburbs of Melbourne, including Melbourne s central business district. Drinking water is supplied to our customers via an extensive, largely underground network of over 4,800 kilometers of water mains, as well as associated valves, holding tanks, pumping stations and secondary disinfection plants. Our priority as an exceptional service provider is to manage and operate this network so that our customers continue to reliably receive the high quality, safe drinking water for which Melbourne has long been renowned. The information presented in this report explains the sources of our drinking water, how it is treated so that it is safe to consume without further treatment, and demonstrates in detail how the quality consistently meets and surpasses drinking water quality standards and targets. Our water quality management processes are endorsed through an uninterrupted history of successfully retaining drinking water HACCP certification and compliance of our water quality Risk Management Plan with Victoria s Safe Drinking Water Act Throughout we routinely tested over 3,000 water samples, most of which were obtained from customers premises. I am pleased to report that this independent chemical and microbial testing continued to demonstrate that the quality of our drinking water supply surpasses standards of the Safe Drinking Water Act 2003 and associated Safe Drinking Water Regulations. Details of the testing undertaken and results obtained form a major part of this report. Further to monitoring the supplied water quality, we also rely upon feedback from customers to advise of local issues that may arise. Such feedback is recorded as water quality related customer complaints. During were received complaints per 100 customers. City West Water is committed to reliably providing high quality and safe drinking water to all our customers and community. I am confident that you will find the information contained in this report helpful in better understanding the great quality of our drinking water supply. David Ryan Managing Director As part of the management processes we have a comprehensive monitoring program that allows us to verify the quality of the drinking water being supplied, as well as identify potential improvements to benefit our customers and community. 2

5 1. Introduction With this publically available report City West Water (CWW) complies with section 23 of the Safe Drinking Water Act 2003 which requires public disclosure of all water quality monitoring information. City West Water is one of three metropolitan water retailers established under section 85(1A) of the Water Act 1989 (Vic). Our Board of Directors is appointed by the Victorian Government and is responsible for setting and overseeing the implementation of the policies, objectives and strategies of the business. We provide drinking water, trade waste, recycled water, stormwater and sewerage services to approximately 444,000 residential and non-residential customers in Melbourne s inner and western suburbs and central business district. Melbourne Water provides City West Water with a bulk water supply and a waste water treatment service. Melbourne Water manages the water catchments and dams, as well as a network of large water mains that interconnect with our own water supply network. This interconnection means that risks associated with water supply are shared between the wholesaler (Melbourne Water) and retailer (City West Water). To manage these risks and to clearly assign the rights and obligations of both parties, we have a contractual arrangement (the Bulk Water Supply Agreement) with Melbourne Water, as well as cross business contingency plans and operational arrangements. Our management of the water supply system and drinking water quality is given the highest priority to reflect public health considerations and community expectations. Our management of the drinking water supply closely follows the risk management principles outlined in Victoria s Safe Drinking Water Act 2003 and associated Safe Drinking Water Regulations. This commitment to safeguarding drinking water quality has continued to be independently recognised through consistent retention of our internationally recognised Hazard Analysis and Critical Control Points (HACCP) certification. 1.1 Characterisation of the system Source water system The water supply originates from Melbourne s well established water supply catchment and reservoir system, which has provided the city with a reliable, high quality water supply for many years. This extensive system, managed by Melbourne Water, lies mainly to the east of Melbourne and extends as far as Thomson Reservoir, approximately 120 kilometres from our service area. More specifically, water is supplied to City West Water from three major storages within the system. Two of the storages, Silvan Reservoir (near Mount Dandenong) and Sugarloaf Reservoir (near Yarra Glen), are east of Melbourne. The third, Greenvale Reservoir, is to the north, near Somerton. The relative proportion of water supplied to us from the three reservoirs can vary, depending on factors such as local water demands, weather conditions, maintenance works and longer term population changes. Over the last decade or so, on average about 25 per cent of our bulk supply has come from Silvan, 25 per cent from Greenvale and 50 per cent from Sugarloaf. During these percentages were 24, 14 and 62, respectively. The supply from Silvan Reservoir originates from protected, natural catchments (including the Thomson and Upper Yarra catchments) where activities such as industry, farming, urbanisation and tourism (which could pollute the water supply) are highly restricted. Greenvale Reservoir does not have a catchment, and receives its water supply from Silvan Reservoir. Long storage periods (ranging between months and years) in these pristine reservoirs enhance water quality. As a result, the only active water treatment process that is applied to this water is chlorination (chlorine gas at Silvan; sodium hypochlorite at Greenvale) and ph correction with lime. Sugarloaf Reservoir draws most of its water from the middle reaches of the Yarra River where the catchment is unprotected, containing urban areas, light industry and agricultural activities. A smaller proportion also comes from Maroondah Reservoir via the Maroondah Aqueduct. On average, the source waters pumped into Sugarloaf Reservoir are stored for months before being treated (via aluminium-based coagulation and flocculation, sand filtration, gas chlorination and ph correction with lime) at Melbourne Water s nearby Winneke water treatment plant. Melbourne Water adds fluoride to all of City West Water s bulk water in line with the requirements of the Victorian Health (Fluoridation) Act (1973). This is in the form of fluorosilicic acid at both the Silvan Reservoir supply and Winneke water treatment plant. 3

6 The quality of the bulk water supply is monitored by Melbourne Water before it enters City West Water s distribution system. This monitoring has two components: sites upstream of treatment, comprising rivers, streams, aqueducts and reservoirs. These sites are monitored at varying frequencies, largely to characterise overall long term background water quality and to monitor for seasonal and possible longer term changes. Parameters tested include organic chemicals, nutrients and microbes. sites downstream of water treatment, where the monitoring is more intense than at upstream sites and is largely focussed on verifying the quality of post-treatment product water. Frequencies of this monitoring range between continuous at chlorine dosing points, daily and weekly, depending on the sites and parameters measured (for example, microbial testing, water clarity and purity) City West Water system We distribute water to over 1 million people. The water is distributed through an extensive network of over 4,800 kilometres of water mains, 10 pumping stations, 8 holding tanks (or service reservoirs/tanks) and 5 secondary chlorination plants. This network encompasses central and western Melbourne, including inner suburbs such as Fitzroy, Collingwood, Richmond and the central business district, to outer western suburbs as far west as Little River. The network is fully enclosed, protecting the water from possible contamination during its delivery to customers. For the purpose of water quality monitoring our 714 square kilometre service area is divided into 15 water sampling localities (refer Figure 1.1) based on sources of water supply and similar pressure. The overall water supply system and water delivery arrangements during the past year have continued unchanged from preceding years. Figure 1.1 City West Water s water service area showing its 15 water sampling localities and sources of bulk water supply. KEY TO LOCALITIES 1 Werribee 1A Little River 2 Altona 2A Werribee South 3A Maribyrnong 3B Williamstown 4 Deer Park 5 Caroline Springs 5A Taylors Lakes 6 East Keilor 7A Tullamarine 9A Strathmore 9B Moonee Ponds 11 Parkville 54 Richmond BOUNDARY ROAD WESTERN HIGHWAY CALDER PARK THUNDERDOME 5A 5 CALDER HIGHWAY ST ALBANS ROAD Greenvale Reservoir TULLAMARINE AIRPORT WESTERN HIGHWAY 7A BRIMBANK PARK 6 3A TULLAMARINE FREEWAY ESSENDON AIRPORT BUCKLEY STREET 9A 4 9B FLEMINGTON RACECOURSE Sugarloaf Reservoir ZOOLOGICAL GARDENS 11 HODDLE STREET Silvan Reservoir DOHERTYS ROAD SAYERS ROAD FITZGERALD ROAD OLD GEELONG ROAD 3B PRINCES HIGHWAY POINT COOK ROAD 2A 1A WESTERN TREATMENT PLANT 4

7 The water supply source(s) for each of our 15 water sampling localities are shown in Table 1.1 Table supply sources for our water sampling localities Water sampling locality Source water Treatment plant Altona Caroline Springs Deer Park East Keilor Little River Maribyrnong Moonee Ponds Parkville Richmond Strathmore Taylors Lakes Tullamarine Werribee Werribee South Williamstown Yarra River; Maroondah, Silvan & Greenvale Reservoirs Yarra River; Maroondah & Greenvale Reservoirs Yarra River; Maroondah, Silvan & Greenvale Reservoirs Yarra River; Maroondah, Silvan & Greenvale Reservoirs Yarra River; Maroondah, Silvan & Greenvale Reservoirs Yarra River; Maroondah & Silvan Reservoirs Yarra River; Maroondah & Silvan Reservoirs Yarra River; Maroondah & Silvan Reservoirs Yarra River; Maroondah & Silvan Reservoirs Yarra River; Maroondah, Silvan & Greenvale Reservoirs Yarra River; Maroondah & Greenvale Reservoirs Yarra River; Maroondah & Greenvale Reservoirs Yarra River; Maroondah, Silvan & Greenvale Reservoirs Yarra River; Maroondah, Silvan & Greenvale Reservoirs Yarra River; Maroondah & Silvan Reservoirs Winneke Silvan Greenvale Winneke Greenvale Winneke Silvan Greenvale Winneke Silvan Greenvale Winneke Silvan Greenvale Winneke Silvan Winneke Silvan Winneke Silvan Winneke Silvan Winneke Silvan Greenvale Winneke Greenvale Winneke Greenvale Winneke Silvan Greenvale Winneke Silvan Greenvale Winneke Silvan Population supplied (2011 census) 97,611 87,947 53,687 38, ,272 68, ,305 20,646 8,917 63,394 9, , ,996 5

8 2. Water treatment and quality management system 2.1 Water treatment The water quality treatment processes used for City West Water s source or bulk water supply are outlined in Section Notwithstanding Melbourne Water s source or bulk water disinfection by chlorination, additional secondary chlorination (using liquid sodium hypochlorite) is undertaken within our service area by: City West Water, with a further 5 secondary chlorination plants servicing the water sampling localities of East Keilor, Little River, Richmond, Werribee and Werribee South. In addition, the local water supply at Little River is dosed with gaseous carbon dioxide in order to assist with maintaining neutral ph levels. Melbourne Water, with 4 secondary chlorination plants servicing the water sampling localities of Werribee, Deer Park, Caroline Springs and Altona. Table 2.1 summarises the water treatment processes used on the water supplied to each water sampling locality. Table 2.1 Drinking water treatment processes Drinking Water Treatment Processes Clarification Filtration Disinfection Other Added Substances Treatment plant # Coagulation and flocculation Sand filtration chlorination ph correction fluoridation alum chlorine gas chlorine liquid (sodium hypochlorite) lime fluorosilicic acid Winneke X X X X X X X X X Greenvale X X X* X* X Silvan X X X X X X *chlorination at Greenvale was changed from gas to liquid in January 2017 # treatment plants applicable to individual localities are shown in Table Issues No adverse water treatment issues originated within City West Water s service area during

9 3. Emergency, incident and event management This part of the report is for reporting emergencies, incidents and events that may have led to known or suspected contamination of the drinking water supply, including those that were reported to Department of Health and Human Services (DHHS) in line with Section 22 of the Safe Drinking Water Act We made two such reports in On 3 January CWW detected E.coli of 1 organism per 100mL at Holden water supply tank (part of the supply to Taylors Lakes water sampling locality). On 4 January it was reported to DHHS and the following actions took place in line with Schedule 2 of the Safe Drinking Water Regulations 2015: -- Holden tank was isolated, inspected and dosed with chlorine; -- Melbourne Water s upstream treatment processes and water quality data was verified; -- resampled at the tank and downstream at customers properties. The outcome from these actions indicated no evidence (apart from the initial E. coli detection) to support that the water supply had been contaminated. Therefore, in line with Schedule 2 of the Safe Drinking Water Regulations 2015 it was concluded that the detection was a false positive. City West Water commissioned a comprehensive health risk assessment reviewed by an independent toxicologist, and an independent review of our processes to prevent similar events in the future. The independent review by the expert toxicologist found that: any adverse health outcomes caused by the short term consumption of the recycled water were extremely unlikely; the health risk assessment was well conducted and provided a sound assessment of the risks of the short-term exposure to recycled water. City West Water provided the toxicologist s review to DHHS which concluded satisfaction with the findings. The independent review of our processes has led to implementation of changes to our management of dual supply systems to better safeguard the drinking water supply. In mid-november 2016, Class A recycled water was supplied for the first time in the West Wyndham dual pipe supply network, to over 4000 properties. The recycled water is provided for external watering uses and toilet flushing. Between 16 and 21 December 2016 it was found that four residential properties in the Wyndham Vale / Manor Lakes area had been incorrectly connected to the dual pipe supply system. The customers were supplied via property specific cross connections, with an approximately 50/50 mixture of Class A recycled water and drinking water into their household drinking water supply. The cause was identified as incorrect connections to the separate recycled water and drinking water mains at the supply point to each property. These cross connections were corrected at each property on the same day as they were identified. In cooperation with DHHS, City West Water has maintained communications with the affected customers. 7

10 4. Drinking Water Quality Monitoring A significant part of our water supply activities involves monitoring the quality of the water being supplied to customers. We have a water monitoring program of day to day sampling and testing from many locations throughout the distribution network of 15 water sampling localities, including some 450 purpose built sampling fittings (referred to as customer taps ) located at the point of supply, adjacent to water meters at properties across our service area. In addition, Melbourne Water monitors the quality of bulk water supplies at points upstream of delivery points to City West Water. The results of all these tests are scrutinised under the Bulk Water Supply Agreement between City West Water and Melbourne Water. Between 1 July 2016 and 30 June 2017, we routinely collected and tested over 3,000 microbiological and 900 physical/chemical water samples from customer taps, mains and service reservoirs/ tanks. This was undertaken under contract by a government approved, specialised and quality certified laboratory. The extent of this monitoring was based on requirements of Safe Drinking Water Regulations 2015 as well as guidance from the Australian Drinking Water Guidelines 2011 (ADWG 2011), including consideration of locality population numbers for bacterial monitoring. As well as guiding the design of monitoring programs, ADWG 2011 provides a basis for assessing the quality of drinking water. Microbiological assessment is based principally on the bacterium Escherichia coli (E. coli), which is considered to definitively indicate the presence of faecal contamination and, therefore, health risk. Physical/chemical assessment and monitoring is based on a combination of parameters that indicate physical/aesthetic characteristics, such as ph, colour and turbidity (the clarity of the water), as well as the chemical quality of the water (i.e. levels of chlorine, iron, fluoride, dissolved salts, aluminium, copper and other heavy metals). Contact information for obtaining further details of all water quality testing outlined in this report is provided in Further Information on page 24. Under Safe Drinking Water Regulations 2015 sample results from reticulation sites such as water mains and service reservoirs/ tanks that are both spatially and hydraulically within individual water sampling localities, are required to be added to the associated customer tap data. City West Water s sampling sites (other than customer taps) and the water sampling locality to which they are associated for water quality performance reporting purposes are listed in Table 4.1 as follows: Table 4.1 City West Water s sampling sites (other than customer taps) and associated water sampling localities Sampling site Little River elevated tank Little River ground level tank no. 1 Little River ground level tank no. 2 Hillside elevated tank Cowies Hill elevated tank Ballan Road tank Werribee South elevated tank Werribee South ground level tank Werribee South main at Maltby bypass Sampling site location and water sampling locality to which water quality data are included Little River Little River Little River Taylors Lakes Werribee Werribee Werribee South Werribee South Werribee South 8

11 5. Drinking Water Quality Standards Since 1 July 2004, the management of drinking water in Victoria has been governed by the Safe Drinking Water Act Under this Act, Safe Drinking Water Regulations specifies scheduled water quality standards for a number of water quality parameters. The standards currently in place are listed in table 4.2: The tables in parts 5.1 to 5.3 report the overall compliance of water quality standard parameters against the water quality scheduled standards specified in Victoria s Safe Drinking Water Regulations Table 5.1 Water quality parameters, standards and frequency of sampling Water quality parameter Standard (Regulations 2015) Escherichia coli (E. coli) No E. coli per 100mL of drinking water, with the exception of any false positive sample Relevant sampling frequency for each locality one sample per week Trihalomethanes Less than or equal to 0.25 mg/l of drinking water one sample per month Turbidity The 95 th percentile of results for samples any 12 month period must be 5.0 NTU one sample per week 9

12 5.1 Escherichia coli (E. coli) Standard: All samples of drinking water collected are found to contain no Escherichia coli per 100 millilitres of drinking water, with the exemption of any false positive sample. Results: 1 July 2016 to 30 June 2017 Table 5.2 E. coli summary results in drinking water samples obtained from reticulation system sampling sites (customer taps, water mains, service reservoirs/tanks) tested between 1 July 2016 and 30 June 2017 Water sampling locality (locality number) Sampling frequency Number of samples Maximum detected (orgs/100ml) Average Number of detections and investigations conducted (s. 22) # Number of samples where standard was not met (s.18) # Altona (2) >weekly 303 <1 <1 0 0 Caroline Springs (5) >weekly 277 <1 <1 0 0 Deer Park (4) >weekly 182 <1 <1 0 0 East Keilor (6) >weekly 145 <1 <1 0 0 Little River (1A) >weekly 119 <1 <1 0 0 Maribyrnong (3A) >weekly 356 <1 <1 0 0 Moonee Ponds (9B) >weekly 224 <1 <1 0 0 Parkville (11) >weekly 368 <1 <1 0 0 Richmond (54) >weekly 105 <1 <1 0 0 Strathmore (9A) >weekly 78 <1 <1 0 0 Taylors Lakes (5A) >weekly 235 1* <1 1* 0 Tullamarine (7A) >weekly 78 <1 <1 0 0 Werribee (1) >weekly 444 <1 <1 0 0 Werribee South (2A) >weekly 117 <1 <1 0 0 Williamstown (3B) >weekly 144 <1 <1 0 0 # s.22: as per Section 22 of the Safe Drinking Water Act (2003). s.18: as per Section 18 of the Safe Drinking Water Act (2003) *Refer to preceding Part 3 for further information. E. coli reticulation system data demonstrate compliance with the standard (100% samples with no E. coli) in each of City West Water s 15 water sampling localities between 1 July 2016 and 30 June Sampling frequencies in each locality exceeded that prescribed by the Safe Drinking Water Regulations 2015 (i.e. one sample per week in each locality). This was done in order to meet the more intense surveillance of internationally recognised population based frequencies, as advocated in ADWG

13 5.2 Total trihalomethanes Trihalomethanes (THMs) are disinfection by-products that are the result of chlorine reacting with substances in water. Standard: Total trihalomethanes less than or equal to 0.25 milligrams per litre of drinking water. Results: Total trihalomethanes 1 July 2016 to 30 June 2017 Table 5.3 Total trihalomethanes summary results in drinking water samples obtained from reticulation system sampling sites (customer taps, water mains, service reservoirs/tanks) tested between 1 July 2016 and 30 June 2017 Water sampling locality (locality number) Frequency of Sampling Number of samples Drinking water quality standard (mg/l) Maximum (mg/l) Average (mg/l) Number of samples where standard was not met (s.18) # Altona (2) monthly Caroline Springs (5) monthly Deer Park (4) monthly East Keilor (6) monthly Little River (1A) >fortnightly Maribyrnong (3A) monthly Moonee Ponds (9B) monthly Parkville (11) monthly Richmond (54) monthly Strathmore (9A) monthly Taylors Lakes (5A) >monthly Tullamarine (7A) monthly Werribee (1) >fortnightly Werribee South (2A) >fortnightly Williamstown (3B) monthly # s.18: as per Section 18 of the Safe Drinking Water Act (2003) Total trihalomethanes data demonstrate compliance with the standard (0.25 mg/l) in each of City West Water s 15 water sampling localities between 1 July 2016 and 30 June

14 5.3 Turbidity Standard: The 95 th percentile of results for samples in any given 12 month period must be less than or equal to 5.0 Nephelometric Turbidity Units (NTU). Results: Turbidity 1 July 2016 to 30 June 2017 Table 5.4 Turbidity summary results in drinking water samples obtained from reticulation system sampling sites (customer taps, water mains, service reservoirs/tanks) tested between 1 July 2016 and 30 June 2017 Water sampling locality (locality number) Frequency of Sampling Number of samples Maximum turbidity in a sample (NTU) 95th percentile of turbidity results in any 12 months (NTU) Number of 95th percentile results in any 12 months above standard (s.18) # Altona (2) weekly Caroline Springs (5) weekly Deer Park (4) weekly East Keilor (6) weekly Little River (1A) >weekly Maribyrnong (3A) weekly Moonee Ponds (9B) weekly Parkville (11) weekly Richmond (54) weekly Strathmore (9A) weekly Taylors Lakes (5A) >weekly Tullamarine (7A) weekly Werribee (1) weekly > Werribee South (2A) weekly > Williamstown (3B) weekly # s.18: as per Section 18 of the Safe Drinking Water Act (2003). Turbidity data demonstrate compliance with the standard (95 th percentile 5 NTU) in each of City West Water s 15 water sampling localities between 1 July 2016 and 30 June Summary performance against water quality standards During , City West Water met the monitoring and water quality requirements of 2015 Safe Drinking Water Regulations for drinking water samples obtained from reticulation system sampling sites (water mains, customer taps, service reservoirs/tanks). A Section 22 notification with respect to an E.coli detection was made however, it was found to be a false positive (refer Part 3). 12

15 6. Other water quality standards (algae toxin, pathogen, chemical or substance that may pose a risk to human health) In addition to the water quality parameters designated as standards by the Safe Drinking Water Regulations, we also monitor a range of other microbiological and chemical parameters that provide further information on the overall quality of our drinking water supply. Among such other parameters that were monitored in , those for which there is a health-related ADWG 2011 guideline are listed in Table 6.1. In addition, data on aesthetic and other parameters that provide a more comprehensive characterisation of the water, as well as assisting the needs of customers (e.g. industry, students and researchers) are contained in Part 7 and Appendices A and B. Table 6.1 Other water quality standards (algae toxin, pathogen, chemical or substance that may pose a risk to human health) monitored in drinking water samples obtained from reticulation system sampling sites (water mains, customer taps, service reservoirs/tanks) and tested between 1 July 2016 and 30 June 2017 Parameter Microbiological Vibrio spp. Shigella spp. Yersinia spp. Salmonella spp. Campylobacter spp. Giardia spp. Cryptosporidium spp. Enterococci Coliphage Chemical* ADWG 2011 health guideline these parameters should not be present in drinking water (mg/l) Frequency of testing 3 to 4 samples per month (3 samples per locality per year) Met the guideline? yes (none detected) Arsenic 0.01 annually per locality yes (not detected) Cadmium annually per locality yes (not detected) Chlorine 5 >weekly per locality yes Chromium 0.05 annually per locality yes (not detected) Copper 2 annually per locality yes Cyanide 0.08 annually per locality yes (not detected) Fluoride 1.5 >fortnightly per locality yes Lead 0.01 annually per locality yes (not detected) Manganese 0.1 fortnightly per locality yes Mercury annually per locality yes (not detected) Nitrate 50 annually per locality yes Sulphate 250 annually per locality yes Zinc 3 (aesthetic only) annually per locality yes *sample numbers, maximum/average/minimum levels and compliance details for each sampling locality are shown in Appendix A tables. Since levels of all health-related parameters tested satisfied ADWG 2011 guideline values for samples from reticulation system sampling sites, no related remedial water quality actions were necessary. As our water supply distribution network is completely enclosed, any monitoring for organic chemicals (including pesticides) and radioactivity is undertaken at locations upstream of this network. Melbourne Water tests for these substances with respect to its major storage reservoirs such as Silvan and Sugarloaf, where the potential for contamination is greater. Results of this monitoring are provided to City West Water. No significant detections (with respect to ADWG 2011 guidelines) in the bulk water supply were reported during

16 7. Aesthetic characteristics Monitoring results for the aesthetic water quality parameters comprising ph, colour, hardness, alkalinity and iron are shown in Table 7.1. Note that our colour tests are reported as apparent colour while the ADWG 2011 guideline of 15 platinum cobalt units (PCU) refers to true colour. Due to the omission of a filtering step in the test for apparent colour, the subsequent result values are at least equal to, but not less than, the equivalent true colour values. As a result, true colour compliance with respect to the ADWG 2011 guideline is assured in all cases where apparent colour levels are within the guideline. Past investigations have shown that for Melbourne s water supply, an apparent colour level of 25 PCU is equivalent to a true colour level of 15 PCU. Table 7.1 Detailed monitoring results for ph, apparent colour, hardness, alkalinity and iron in drinking water samples obtained from reticulation system sampling sites (water mains, customer taps, service reservoirs/tanks) and tested between 1 July 2016 and 30 June 2017 Water Sampling Locality (locality number) Parameter Frequency of Sampling Number of samples Minimum* Maximum* Aesthetic operating range Altona (2) ph fortnightly or # apparent colour fortnightly 26 <2 6 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly <0.3mg/L Caroline Springs (5) ph fortnightly or # apparent colour fortnightly 26 <2 6 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly 26 < <0.3mg/L Deer Park (4) ph fortnightly or # apparent colour fortnightly 26 <2 6 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly 26 < <0.3mg/L East Keilor (6) ph fortnightly or # apparent colour fortnightly 26 <2 8 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly 26 < <0.3mg/L Little River (1A) ph >fortnightly or # apparent colour >fortnightly 62 <2 4 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron >fortnightly <0.3mg/L 14

17 Water Sampling Locality (locality number) Parameter Frequency of Sampling Number of samples Minimum* Maximum* Aesthetic operating range Maribyrnong (3A) ph fortnightly or # apparent colour fortnightly 51 <2 6 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly 51 < <0.3mg/L Moonee Ponds (9B) ph fortnightly or # apparent colour fortnightly 26 <2 8 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly <0.3mg/L Parkville (11) ph fortnightly or # apparent colour fortnightly 26 <2 18 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly <0.3mg/L Richmond (54) ph fortnightly or # apparent colour fortnightly 26 <2 10 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly <0.3mg/L Strathmore (9A) ph fortnightly or # apparent colour fortnightly 25 <2 10 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly <0.3mg/L Taylors Lakes (5A) ph >fortnightly or # apparent colour >fortnightly 38 <2 8 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron >fortnightly <0.3mg/L Tullamarine (7A) ph fortnightly or # apparent colour fortnightly 26 <2 8 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly 26 < <0.3mg/L 15

18 Water Sampling Locality (locality number) Parameter Frequency of Sampling Number of samples Minimum* Maximum* Aesthetic operating range Werribee (1) ph >fortnightly or # apparent colour >fortnightly 50 <2 4 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron >fortnightly <0.3mg/L Werribee South (2A) ph >fortnightly or # apparent colour >fortnightly 62 <2 16 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron >fortnightly <0.3mg/L Williamstown (3B) ph fortnightly or # apparent colour fortnightly 26 <2 6 <25Pt/Co** hardness annually <200mg/L alkalinity annually NA iron fortnightly 26 < <0.3mg/L * Units: ph (units); apparent colour (platinum cobalt units); hardness (mg/l as calcium carbonate); alkalinity (mg/l as calcium carbonate); iron (mg/l). # tolerable upper value of 9.2 where there are cement lined water mains. **Guideline set for True Colour (15 PCU) however Apparent Colour is measured (with a benchmark guideline of 25 PCU). All water colour, hardness and iron monitoring data complied with the respective aesthetic operating ranges levels of 25 PCU, 200 mg/l and 0.3 mg/l. There is no guideline for alkalinity. Of the 497 samples tested for ph, there were 8 instances where ph readings were not within the ADWG 2011 guideline range of 6.5 to 8.5. Two of these exceeded 8.5 (maximum 8.9) but not the tolerable upper value of 9.2, whilst another five were marginally below 6.5 (minimum 6.4). Such minor variations do not have health implications as, according to ADWG 2011, adverse health effects may occur at ph levels less than 4 or greater than

19 8. Analysis of results trends This part of the report examines: a) trends over time of water quality parameters tested that are designated as scheduled standards in Safe Drinking Water Regulations (2015). b) trends over time and between localities of parameters listed in Appendix A tables that have a corresponding Victorian standard or ADWG 2011 guideline. Data analysed in this section are based on drinking water samples obtained from reticulation system sampling sites (customer taps, water mains and service reservoirs/tanks). A comprehensive outline of our monitoring data for individual localities, together with monitoring frequencies, Victorian standards and ADWG 2011 guidelines for both health-related and aesthetic water quality data, is contained in Appendix A tables. Contact information for obtaining further details of all water quality testing outlined in this report is provided in the Further Information section on page Historical compliance of standard parameters Table 8.1 summarises trends over time (and extent of compliance) of water quality parameters that are scheduled standards in Safe Drinking Water Regulations (2015). Table 8.1 Compliance time trends of scheduled standard parameters Parameter Standard (2015 Regulations) E. coli <1 per 100ml Trihalomethanes 0.25 mg/l Turbidity 5* Localities compliant (% of customers supplied with compliant water) / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) 15 / 15 (100%) * 95th percentile not to exceed 5.0 NTU. 17

20 8.2 Parameter trends over time and between localities Analysis of parameter trends over time and between localities is used as a tool to better understand and possibly highlight water quality issues throughout our service area. This part of the report looks at such trends over the past three years in terms of the key parameters listed in Appendix A tables. Graphical representations of trends are contained in Appendix B and briefly discussed below. E. coli (refer Figure B.1 in Appendix B) E. coli performance in our drinking water has consistently complied with the 2015 Victorian standards in all water sampling localities. Free chlorine (refer Figure B.2 in Appendix B) All of our drinking water supply is disinfected with chlorine. The more active form (free chlorine) is present in all water sampling localities, with levels well within the maximum ADWG 2011 guideline of 5 mg/l. Nevertheless, average levels amongst individual localities can be markedly different; this being largely due to relative proximity to chlorine dosing points. For example, the Taylors Lakes and Tullamarine localities are situated close to primary chlorination at Greenvale Reservoir, while the East Keilor and Werribee South localities are served by secondary rechlorination plants. Year-to-year variations within water sampling localities reflect changes to chlorine dosing rates and bulk water sources. Aluminium (refer Figure B.3 in Appendix B) Overall aluminium levels in the water supply are low. Apparent variations at these levels are considered to be related to natural differences in the catchments rather than from artificial treatment dosing. For example, aluminium is only used in water treatment at the Winneke Treatment Plant, yet the water sampling localities more likely to receive water from this source (Moonee Ponds, Parkville, Altona, Werribee) do not exhibit markedly higher aluminium levels as compared with other localities. Arsenic, cadmium, chromium, cyanide, lead, mercury, zinc These substances have been monitored on an annual basis. As shown in the Appendix A tables, test results have consistently been either well within guideline levels or below analytical detection limits. Chloride (refer Figure B.4 in Appendix B) Colour (refer Figure B.5 in Appendix B) ADWG 2011 refers to true colour of water; however we have continued the historical practice of measuring the more conservative apparent colour, which gives higher readings. Nevertheless, our average apparent colour levels have been within the ADWG 2011 True Colour guideline of 15 PCU. Higher colour levels in the Richmond locality are associated with its traditional bulk supply source from Silvan Reservoir. Average colour levels are generally consistent within individual sampling localities. Copper (refer Figure B.6 in Appendix B) Copper levels in the water supply are low and consistently well within the ADWG 2011 health and aesthetic guidelines. Electrical conductivity (EC) (refer Figure B.7 in Appendix B) We measure EC as a surrogate for total dissolved solids (TDS). ADWG 2011 advises that its TDS guideline level of 600 mg/l can be substituted by an EC level of approximately 900 µs/cm. EC levels are quite low and relatively consistent within each water sampling locality. Slight trend of increased EC levels reflects greater supply from Sugarloaf/Winneke. Fluoride (refer Figure B.8 in Appendix B) Fluoride levels in the water supply are the result of fluoridation of the bulk supply (refer Section 1.1.1). Dosing is normally controlled such that levels are generally maintained between approximately 0.9 and 1.0 mg/l. Average fluoride levels in were lower due to a malfunction of fluoride dosing at Winneke treatment plant in March 2016, affecting most water sampling localities. These lower levels were maintained in due to more conservative dosing as well as periods of absence of dosing. Hardness (refer Figure B.9 in Appendix B) Water hardness levels are quite low and relatively consistent within each water sampling locality. Iron (refer Figure B.10 in Appendix B) Overall, slightly higher iron levels in the Taylors Lakes and Richmond water sampling localities are consistent with their source water comprising more of the relatively greater iron containing water from Silvan and Greenvale reservoirs. Nevertheless, variations occur due to changes in bulk water sources. A decline in iron levels throughout reflects an overall greater supply from Sugarloaf/Winneke. Chloride levels are quite low (well within guideline levels) and relatively consistent amongst the water sampling localities. 18

21 Manganese (refer Figure B.11 in Appendix B) Manganese levels in the water supply are low and consistently well within the guidelines. Nitrate (refer Figure B.12 in Appendix B) Nitrate levels in the water supply are low and consistently well within the guidelines. ph (refer Figure B.13 in Appendix B) Average ph levels in all localities are within guideline levels. The slightly higher levels in Werribee South are consistent with the presence of cement lined mains. Note that Little River also has cement lined mains but its ph is being controlled by dosing the local water supply with carbon dioxide gas. Sodium (refer Figure B.14 in Appendix B) Sodium levels are quite low and relatively consistent among the water sampling localities. Turbidity (refer Figure B.15 in Appendix B) Turbidity levels in all localities continue to be less than the standard. Variations between individual water sampling localities are a reflection of their source waters. For example, localities with lower turbidity tend to be supplied more from Sugarloaf/ Winneke, while higher turbidity localities tend to be supplied to a greater extent from Silvan and Greenvale reservoirs. Note that comparisons of levels with subsequent years may be inappropriate due to the changed standard. Sulphate (refer Figure B.16 in Appendix B) Sulphate levels are quite low and relatively consistent within each water quality locality. Lower sulphate (as well as sodium, hardness, conductivity and chloride as per earlier Figures) levels in Caroline Springs, Richmond and Taylors Lakes localities are a reflection of the Silvan reservoir source. At the same time, higher turbidity, iron and colour in these localities also reflects Silvan as the source of the water. Total trihalomethanes (refer Figure B.17 in Appendix B) Total trihalomethanes concentrations are relatively low (in comparison with the Victorian standard) and consistent among water sampling localities. Localities with higher levels tend to be more remote from primary chlorination. 19

22 9. Complaints relating to water quality In , City West Water received 435 complaints related to water supply quality. The various categories of complaints were distributed as shown in Table 9.1. Table 9.1 Water quality related customer complaints received over the last three years Complaint category Discoloured water Numbers received Comparison with previous reporting periods Increase of 151 from previous reporting period. Comments Complaint recording procedure was clarified. Follow up calls are now recorded separately. Also, all customers calls from a single incident are now recorded. Taste/odour 43 (5 chlorine)* 31 (6 chlorine)* 37 (9 chlorine)* No significant change. Nil. Air in water Other (alleged illness) (blocked filter) (blue-green water) (staining) 7 (1) (3) (1) (2) 6 (0) (6) (0) (0) 1 (0) (1) (0) (0) Total Increase of 28 from previous reporting period. No significant change. Increase of 192 from previous reporting period. As per discoloured water. Nil. As per discoloured water. No. of properties 445, , , Complaints per 100 properties * Number of complaints received of chlorine taste or odour. The water quality complaints received during in each water sampling locality are shown in Table

23 Table 9.2 Water quality related customer complaints received during per water sampling locality. Water sampling locality (Locality number) Discoloured water Taste/odour Numbers received Air in water Other (alleged illness) (blocked filter) (blue-green water) (staining) Total complaints Altona (2) Caroline Springs (5) Deer Park (4) East Keilor (6) Little River (1A) Maribyrnong (3A) Moonee Ponds (9B) Parkville (11) Richmond (54) Strathmore (9A) Taylors Lakes (5A) Tullamarine (7A) Werribee (1) Werribee South (2A) Williamstown (3B) Complaints and responses We provide individual responses to water quality related complaints. These can range between verbal clarification of perceived issues to onsite investigations and remedial action. In terms of the major complaint categories, our responses are as follows: Discoloured (e.g. brown) water Discoloured water is generally caused by the suspension of accumulated natural sediments in water mains. It can be triggered by the opening or closing of valves and reinstatement of mains into service following repairs. Discoloured water can also result from older, rusting internal galvanised iron pipes. Calls to City West Water are assessed by trained staff and, where the discoloured water is deemed to be originating from the water main, targeted mains flushing is generally undertaken. Alleged illness Complaints of water related illness are referred to our Water Quality Scientist for detailed discussion, analysis and investigation. Customers may be advised to seek medical advice. White water (air in water) White water (water with a cloudy appearance that clarifies within a few minutes) indicates the presence of tiny, harmless air bubbles. It tends to be associated with maintenance and repair works, when air can enter water pipes. As the aerated water is used by customers, its appearance returns to normal. In the past we often responded to customers concerns with targeted mains flushing, however with increasing emphasis on the need to conserve water, we spend more time on explaining the phenomenon and obtaining customer agreement to not flush water mains. 21

24 Blue-green water On a seemingly random basis, customers at a small number of properties report blue-green water (water that has a cloudy to blue-green appearance, possibly containing blue-green particles, and having an unpleasant bitter taste). This is caused by accelerated corrosion of customers internal copper water pipes and appears to be restricted to cold water pipes. Blue-green water must not be consumed (by drinking or in the preparation of food) because it can cause vomiting. The prolonged consumption of water containing elevated copper levels can have adverse health effects. As blue-green water originates from a property s internal copper pipes, customers can manage the problem by flushing their tap with fresh mains water. This means running their tap until the water becomes clear. Taste or odour A change in taste or odour of tap water can occur occasionally and is generally apparent as a chlorine-like or earthy, musty sensation. Fluctuations in chlorine levels (and hence, the perception of chlorine taste or odour) occur from time to time, largely due to changed water demands and flow rates. Our response to customers reporting chlorine taste/odour involves providing an explanation, as well as considering changes to chlorine dosing. Other tastes/odours can result when water flows are slower and during flow reversals in large pipes. In such cases the cause is identified and, where appropriate, a combination of targeted flushing and/or changes to flow regimes are implemented. In certain cases, corrosion of copper pipes can lead to perforation and leakage. Neither the cause(s) of, nor solution to this international and Australia wide copper corrosion phenomenon are well known (apart from replacement of corroding pipes). We assist customers experiencing copper pipe corrosion by testing copper levels in their water and providing advice on how to best manage the issue of blue-green water. If customers are experiencing blue-green water or have other water quality concerns, they are asked to call us on for further information and advice. 22